Ultrasound imaging is widely used in a range of medical applications. One area in which ultrasound imaging is used is to guide biopsy procedures. A biopsy typically involves identifying an abnormality of interest, such as suspicious solid mass, a distortion in the structure of a body tissue, or an area of abnormal tissue change. A needle or other fine member may be inserted into the abnormality and used to withdraw a small tissue sample for investigation.
A problem with the use of ultrasound to guide a needle or wire in any of these procedures, or like procedures, is that it may be difficult to determine the spatial relationship between the ultrasound image and the needle or wire. In particular, it may be difficult to determine the relationship between the scan plane of an ultrasound image and a needle or other fine member when the needle or other fine members is out of the plane of the ultrasound image.
A similar problem arises when using images acquired by a freehand ultrasound probe to construct a 3D model of a body. In order form a 3D model of a body as a composite of image data from multiple images corresponding to different scan planes, the locations of the scan planes relative to one another must be known. As the probe is moved, the ultrasound scan plane moves and the region of the body imaged by the probe changes.
The following US patents and publications disclose technology that may be in the general field of this invention:    US 2009/0221908 A1, Glossop    U.S. Pat. No. 6,138,495, Paltieli et al.    U.S. Pat. No. 6,122,538, Sliwa et al.    U.S. Pat. No. 6,338,716, Hossack et al.    U.S. Pat. No. 5,771,896, Sliwa et al.    U.S. Pat. No. 6,517,491, Thiele et al.    Freehand 3D Ultrasound Calibration: A Review, P-W. Hsu, R. W. Prager A. H. Gee and G. M. Treece CUED/F-INFENG/TR 584, University of Cambridge Department of Engineering, December 2007